If nothing is uploaded, where does the processing happen?

In the browser tab, on your own device's processor. The PDF libraries that do the work are downloaded once with the page — after that, they run locally against the file you selected.

Can I use this offline?

Every tool here except PDF to Word will keep working if you disconnect after the page has loaded. That is a direct consequence of nothing being uploaded.

How can I be sure nothing is being sent?

Open developer tools with F12, select the Network tab, and run the tool. You will see the page's own scripts load and then no further requests. You can also simply disconnect from the network and watch it keep working.

How small can you make my PDF?

It depends entirely on what is in it. Scanned documents and image-heavy files often drop by 70 to 90 per cent. A text-only PDF exported from a word processor is already efficient and may barely change — the tool will tell you when that is the case rather than shipping a pointless file.

Will the text still be selectable after compression?

With the Lossless level, yes — nothing about the page content changes. With Balanced, Strong or Target size, pages are re-rendered as images, so text becomes part of the picture and is no longer selectable or searchable. Choose Lossless if searchable text matters more than size.

What does the target size mode actually do?

It tries a sequence of six settings, each combining a lower render resolution with a lower image quality. As soon as one produces a file at or under your target it stops and hands that back. If none of them reach the target, you get the smallest usable version along with a note saying the target was not met.

Why did my file get no smaller?

Some PDFs are already optimised — text-only documents from Word or LaTeX typically are. In that case re-rendering would make the file larger, not smaller, so the tool keeps the better of the two results and tells you it could not improve on it.

Are the page dimensions preserved?

Yes. Even when a page is re-rendered at a lower resolution, the output page keeps the original point size, so the document still prints at the correct physical dimensions.

Compress PDF Without Uploading Anything

Shrink a PDF so it fits an upload limit or an email attachment.

Drop your PDF file here

or browse your device

A single PDF file, up to 150 MB. Files are processed on this device.

The word "upload" does a lot of quiet work on most online PDF sites. You choose a file, it goes to a server you know nothing about, something happens to it there, and a result comes back. This tool does not do that. Nothing is uploaded, at any point, for any reason.

What happens instead is that your browser reads the file directly from your disk into the memory of the tab you are looking at. The compress pdf operation runs there, using your device's own processor, and the finished file is created in that same memory and offered to you as a download.

This is possible because modern browsers are genuinely capable environments. The File API can read local files, WebAssembly and modern JavaScript engines can do real document processing, and the download mechanism can hand back a file that was constructed entirely in the tab. Ten years ago this genuinely required a server. It no longer does.

Almost every PDF that is too large is too large for the same reason: it contains page images at a far higher resolution than anyone will ever look at. A phone photo of a receipt dropped into a document can easily be 8 MB on its own. PDFNova's compressor attacks that directly, and it tells you honestly what it achieved.

There are four levels. Lossless rewrites the file structure without touching a single page, which helps some documents and does nothing for others. Balanced and Strong re-render pages at a lower resolution and quality. Target size keeps trying progressively harder settings until the file fits the number you gave it, which is what you want when a portal refuses anything over 1 MB.

How to compress a PDF file

Add your PDF
Drop in the file you need to shrink. Files up to 150 MB are accepted.
Pick a compression level
Start with Balanced. Choose Lossless if the document must not be re-rendered at all, or Target size if you have a hard limit to meet.
Set your target, if you have one
With Target size selected, enter the ceiling in kilobytes. 1024 KB is about 1 MB, 500 KB is a common email-friendly limit.
Compress
Progress is reported page by page. Larger documents take longer because every page is re-rendered.
Check the numbers and download
The results panel shows the original size, the new size and the saving. Preview the document before downloading to confirm it is still readable.

Why use this compress pdf tool

No transfer to intercept

Because nothing is transmitted, there is no network traffic carrying your document that could be observed anywhere along the way.

Works with no connection

Once the page has loaded you can disconnect entirely and the tool keeps working, which is only possible because nothing is being sent.

No data allowance used

On a metered or mobile connection, processing a 50 MB document costs you nothing beyond loading the page itself.

A real size target

Give the tool a number in kilobytes and it will keep trying harder settings until the output fits, rather than compressing once and leaving you to guess.

It never makes things worse

If aggressive compression produces a larger file than a simple structural rewrite, the smaller of the two is what you get. The result is never bigger than what a plain re-save would give you.

Honest reporting

You are shown the before and after size and the percentage saved. If a document was already well optimised and could not be improved, the tool says so instead of pretending.

Features

Four levelsLossless, Balanced, Strong, and an iterative Target size mode.
Size targetingSix progressively stronger passes are tried until your target is met.
Before and afterEvery run reports the original size, final size and percentage saved.
Preview firstRead the compressed document in the browser before you commit to it.
Cancel mid-runStop a long compression at any point without leaving a partial file behind.

When people use this

Meeting an upload limit

Government portals, job applications and court filing systems routinely cap uploads at 1, 2 or 5 MB. Target size mode exists for exactly this.

Emailing a scanned document

A scanned twenty-page contract can easily exceed 25 MB. Balanced compression usually brings it under a typical mail attachment limit while keeping it perfectly readable.

Publishing to a website

Smaller PDFs load faster for readers on mobile connections and cost you less bandwidth.

Archiving a folder of documents

Compressing before archiving keeps years of paperwork from filling a drive, at a quality level that is still fine to read.

What happens to your file, step by step

When you drop a file onto the upload area, your browser gives the page a reference to it — not the contents, just a handle. Nothing has been read at that point, and certainly nothing sent.

When you press the action button, the page reads the bytes of that file into memory using the browser's File API. This is a local disk read, the same kind any application on your device performs, and it never touches the network.

The processing runs against those bytes inside the tab. Depending on the tool, that means parsing the PDF structure with pdf-lib or rendering pages with pdf.js — both are JavaScript libraries that were downloaded once as part of the page and run entirely on your processor.

The result is assembled in memory as a Blob and given a temporary local address that only your browser knows about. Pressing download copies it from memory to your disk. At no stage in this sequence does your document, or any part of it, travel over the network.

How compression works

The Lossless level loads the document with pdf-lib and re-saves it using cross-reference object streams. This packs the file's internal structure more tightly without altering any page content — useful for documents with a lot of structural bloat, neutral for everything else.

The other levels take a different route. Each page is rendered to a canvas with pdf.js at a chosen scale, encoded as a JPEG at a chosen quality, and embedded into a fresh PDF at the original page dimensions. Target size mode walks through six scale-and-quality pairs from 1.5x at 82 per cent quality down to 0.55x at 34 per cent, stopping at the first one that meets your number. Whatever route is taken, the final output is compared against the plain lossless rewrite and the smaller of the two wins.

Privacy

Your files are not uploaded. When you add a PDF file, your browser reads it from your device into the memory of the tab you are looking at, and the compress pdf operation runs there using your own processor. Nothing is transmitted to any server at any point.

That means there is no file for anyone to store, no retention policy to trust, and no deletion schedule to take on faith. The document exists only in the memory of an open browser tab, and it is released the moment you close it, reload the page, or press start over.

The site uses standard anonymous analytics to count page views and how often each tool is used. Those events record which tool ran and whether it succeeded — never a file name, never file contents, and never anything that could identify a document or the person processing it.

No account is required, so no personal information is collected. There is no profile, no history and nothing tied to an identity, because no identity was ever created.

Security

The strongest security property this tool has is structural: your file never travels anywhere, so there is no transmission to intercept and no server-side copy to breach. This is not a policy that could change — it is a consequence of where the code runs.

You can verify it in about thirty seconds. Open your browser's developer tools with F12, select the Network tab, and use the tool. You will see the page's scripts load — including the PDF libraries, which are fetched on demand the first time a tool runs — and then nothing further. No request carrying your document is ever made.

For a stronger test, disconnect from the network once the page has loaded. The tool will keep working exactly as before, which is only possible because nothing is being sent.

Uploaded files are validated in the browser before anything runs: the extension must match what the tool accepts, the file must not be empty, and it must be within the size limit. Malformed documents produce a clear error and a retry option rather than a silent failure.

What this tool does not do

Being clear about limits is more useful than a feature list that quietly omits them. Any level other than Lossless converts page text into an image, which removes text selection, copy and paste, and searchability. Compression also cannot reduce a file below the size its content fundamentally requires.

If you need capabilities beyond that — redaction, PDF/A conformance, OCR, or scripted batch processing across thousands of documents — dedicated desktop software genuinely earns its licence fee, and this is not trying to replace it. For the specific job of producing a compressed PDF, everything you need is on this page.

Frequently asked questions

If nothing is uploaded, where does the processing happen?: In the browser tab, on your own device's processor. The PDF libraries that do the work are downloaded once with the page — after that, they run locally against the file you selected.
Can I use this offline?: Every tool here except PDF to Word will keep working if you disconnect after the page has loaded. That is a direct consequence of nothing being uploaded.
How can I be sure nothing is being sent?: Open developer tools with F12, select the Network tab, and run the tool. You will see the page's own scripts load and then no further requests. You can also simply disconnect from the network and watch it keep working.
How small can you make my PDF?: It depends entirely on what is in it. Scanned documents and image-heavy files often drop by 70 to 90 per cent. A text-only PDF exported from a word processor is already efficient and may barely change — the tool will tell you when that is the case rather than shipping a pointless file.
Will the text still be selectable after compression?: With the Lossless level, yes — nothing about the page content changes. With Balanced, Strong or Target size, pages are re-rendered as images, so text becomes part of the picture and is no longer selectable or searchable. Choose Lossless if searchable text matters more than size.
What does the target size mode actually do?: It tries a sequence of six settings, each combining a lower render resolution with a lower image quality. As soon as one produces a file at or under your target it stops and hands that back. If none of them reach the target, you get the smallest usable version along with a note saying the target was not met.
Why did my file get no smaller?: Some PDFs are already optimised — text-only documents from Word or LaTeX typically are. In that case re-rendering would make the file larger, not smaller, so the tool keeps the better of the two results and tells you it could not improve on it.
Are the page dimensions preserved?: Yes. Even when a page is re-rendered at a lower resolution, the output page keeps the original point size, so the document still prints at the correct physical dimensions.

Browse every PDF tool, or read the help and FAQ pages. Details of how files are handled are in the privacy policy.